Ionic strength and polyelectrolyte molecular weight effects on floc formation and growth in Taylor–Couette flows

Soft Matter ◽  
2021 ◽  
Author(s):  
Athena E. Metaxas ◽  
Vishal Panwar ◽  
Ruth L. Olson ◽  
Cari S. Dutcher
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Solution Ionic Strength ◽  
Radial Injection ◽  
Couette Cell ◽  
Taylor Couette

A Taylor–Couette cell capable of radial injection was used to study the effects of varying solution ionic strength and polyelectrolyte molecular weight on the polyelectrolyte-driven flocculation of bentonite suspensions.

Antithrombin III Binding to Surface Immobilized Heparin and Its Relation to F Xa Inhibition

1987 ◽  
Vol 58 (04) ◽  
pp. 1064-1067 ◽  
Author(s):  
K Kodama ◽  
B Pasche ◽  
P Olsson ◽  
J Swedenborg ◽  
L Adolfsson ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Surface Coating ◽  
Antithrombin Iii ◽  
Lower Class ◽  
Biologically Active ◽  
High Affinity ◽  
Heparin Coating ◽  
Continuous Surface ◽  
Approximate Molecular Weight

SummaryThe mode of F Xa inhibition was investigated on a thromboresistant surface with end-point attached partially depoly-merized heparin of an approximate molecular weight of 8000. Affinity chromatography revealed that one fourth of the heparin used in surface coating had high affinity for antithrombin III (AT). The heparin surface adsorbed AT from both human plasma and solutions of purified AT. By increasing the ionic strength in the AT solution the existence of high and low affinity sites could be shown. The uptake of AT was measured and the density of available high and low affinity sites was found to be in the range of 5 HTid 11 pic.omoles/cmf, respectively Thus the estimated density of biologically active high and low ailmity heparm respectively would be 40 and 90 ng/cm2 The heparin coating did not take up or exert F Xa inhibition by itself. With AT adsorbed on both high and low affinity heparin the surface had the capacity to inhibit several consecutive aliquots of F Xa exposed to the surface. When mainly high affinity sites were saturated with AT the inhibition capacity was considerably lower. Tt was demonstrated that the density of AT on both high and low affinity heparin determines the F Xa inhibition capacity whereas the amount of AT on high affinity sites limits the rate of the reaction. This implies that during the inhibition of F Xa there is a continuous surface-diffusion of AT from sites of a lower class to the high affinity sites where the F Xa/AT complex is formed and leaves the surface. The ability of the immobilized heparin to catalyze inhibition of F Xa is likely to be an important component for the thromboresistant properties of a heparin coating with non-compromized AT binding sequences.

Interaction of Plasminogen Activators and Plasminogen with Heparin: Effect of Ionic Strength

1993 ◽  
Vol 70 (05) ◽  
pp. 867-872 ◽  
Author(s):  
Dingeman C Rijken ◽  
Gerard A W de Munk ◽  
Annie F H Jie
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Plasminogen Activator ◽  
Plasminogen Activators ◽  
Fibrinolytic System ◽  
Tissue Type ◽  
Single Chain ◽  
Physiological Conditions ◽  
Amino Terminal ◽  
Type Plasminogen Activator

SummaryIn order to define the possible effects of heparin on the fibrinolytic system under physiological conditions, we studied the interactions of this drug with plasminogen and its activators at various ionic strengths. As reported in recent literature, heparin stimulated the activation of Lys-plasminogen by high molecular weight (HMW) and low molecular weight (LMW) two-chain urokinase-type plasminogen activator (u-PA) and two-chain tissue-type plasminogen activator (t-PA) 10- to 17-fold. Our results showed, however, that this stimulation only occurred at low ionic strength and was negligible at a physiological salt concentration. Direct binding studies were performed using heparin-agarose column chromatography. The interaction between heparin and Lys-plasminogen appeared to be salt sensitive, which explains at least in part why heparin did not stimulate plasminogen activation at 0.15 M NaCl. The binding of u-PA and t-PA to heparinagarose was less salt sensitive. Results were consistent with heparin binding sites on both LMW u-PA and the amino-terminal part of HMW u-PA. Single-chain t-PA bound more avidly than two-chain t-PA. The interactions between heparin and plasminogen activators can occur under physiological conditions and may modulate the fibrinolytic system.

Antiheparin Activity of Human Serum and Platelet Factor 4

1973 ◽  
Vol 30 (01) ◽  
pp. 093-105 ◽  
Author(s):  
C.H.J Sear ◽  
L Poller ◽  
F.R.C Path
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Blood Serum ◽  
Whole Blood ◽  
Platelet Rich Plasma ◽  
Gel Filtration ◽  
Normal Serum ◽  
Platelet Factor ◽  
Mean Values ◽  
Antiheparin Activity

SummaryThe antiheparin activity of normal serum has been studied by comparing the antiheparin activities of sera obtained from normal whole blood, platelet-rich plasma and platelet-’free’ plasma with a purified platelet extract during differential isoelectric precipitation and by gel filtration chromatography.The mean values for the activity of PRP-serum and PFP-serum were 106% (S.D. 11) and 10% (S.D. 3) of untreated whole blood respectively. The activity of whole blood serum, PRP serum and whole blood serum plus platelet extract precipitated under identical physical conditions, i.e. pH 7.0, I =0.008, indicating that the activities of the three samples are probably associated with PF4. PF4 precipitated from human platelet extract at pH 4.0, but this is probably due to the difference in the two biochemical environments investigated, i.e. serum and platelet extract.The gel filtration experiments revealed striking similarities between the major antiheparin activities of serum and platelet extract. At physiological pH and ionic strength both activities were associated with high molecular weight material, but at physiological pH and elevated ionic strength both activities behaved as much smaller entities of molecular weight between 25,000 and 30,000 daltons and it seems very likely that both activities are associated with the same molecule, i.e. PF4.

Temperature-Regulated Fluorescence and Association of an Oligo(ethyleneglycol)methacrylate-Based Copolymer with a Conjugated Polyelectrolyte—The Effect of Solution Ionic Strength

2013 ◽  
Vol 117 (46) ◽  
pp. 14576-14587 ◽  
Author(s):  
Sahika Inal ◽  
Leonardo Chiappisi ◽  
Jonas D. Kölsch ◽  
Mario Kraft ◽  
Marie-Sousai Appavou ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Conjugated Polyelectrolyte ◽  
Solution Ionic Strength

Impact of osmotic pressure on the stability of Taylor vortices

2022 ◽  
Vol 933 ◽  
Author(s):  
Rouae Ben Dhia ◽  
Nils Tilton ◽  
Denis Martinand
Keyword(s):  
Osmotic Pressure ◽  
Critical Conditions ◽  
Hydrodynamic Instabilities ◽  
Taylor Vortices ◽  
Dynamic Filtration ◽  
Analytical Criterion ◽  
Permeable Cylinders ◽  
Couette Cell ◽  
Taylor Couette ◽  
The Stability

We use linear stability analysis and direct numerical simulations to investigate the coupling between centrifugal instabilities, solute transport and osmotic pressure in a Taylor–Couette configuration that models rotating dynamic filtration devices. The geometry consists of a Taylor–Couette cell with a superimposed radial throughflow of solvent across two semi-permeable cylinders. Both cylinders totally reject the solute, inducing the build-up of a concentration boundary layer. The solute retroacts on the velocity field via the osmotic pressure associated with the concentration differences across the semi-permeable cylinders. Our results show that the presence of osmotic pressure strongly alters the dynamics of the centrifugal instabilities and substantially reduces the critical conditions above which Taylor vortices are observed. It is also found that this enhancement of the hydrodynamic instabilities eventually plateaus as the osmotic pressure is further increased. We propose a mechanism to explain how osmosis and instabilities cooperate and develop an analytical criterion to bound the parameter range for which osmosis fosters the hydrodynamic instabilities.

Heat transport across a gold nanowire/water interface enhanced by the solution ionic strength

2015 ◽  
Vol 1779 ◽  
pp. 33-38 ◽  
Author(s):  
Susil Baral ◽  
Andrew J. Green ◽  
Hugh H. Richardson
Keyword(s):  
Ionic Strength ◽  
Thermal Resistance ◽  
Temperature Change ◽  
Heat Dissipation ◽  
Pure Water ◽  
Gold Nanowires ◽  
Solution Ionic Strength ◽  
Interface Thermal Resistance ◽  
Ionic Solutes ◽  
Surrounding Liquid

ABSTRACTLithographically fabricated gold nanowires are optically excited with 532nm CW laser and the local temperature change is measured in air, pure water and various concentration aqueous solutions of ionic solutes NaCl, Na2SO4 and MgSO4 using the thermal sensor film of Al0.94Ga0.06N embedded with Er3+ ions. The interface thermal resistance for heat transfer from the excited nanowires into the surrounding liquid is determined from the slopes of the temperature change versus laser intensity plots obtained for the nanowire excitation under various solutions. Addition of ionic solute molecules into the solution decreases the interface thermal resistance and hence leads to increased heat dissipation into the surrounding liquid. Interface thermal resistance decreases exponentially with the ionic strength of solution and saturates around zero for solution ionic strength of 0.3M and higher.

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